Multiple myeloma (MM) embodies a plasma cell disorder characterized by neoplastic proliferation of a single clone of plasma cells engaged in the production of a monoclonal immunoglobulin, usually monoclonal IgG or IgA. MM accounts for 1% of all malignant disease and slightly more than 10% of all hematologic malignancies. The annual incidence of multiple myeloma is 4 per 100,000. The annual incidence is linked to aging population. The median age of patients at the time of diagnosis is 61 years. MM is most common in men, and in individuals of African ancestry.
MM remains a disease for which a cure is a rarity. Most patients succumb to their disease within 36-48 months from the time of diagnosis. The limitations of effective therapy for MM are primarily associated with a low cell proliferation rate and multi-drug resistance. Therapy for multiple myeloma includes induction, maintenance, and supportive aspects. The induction portion of the treatment aims at reducing the tumor volume and achieving a plateau phase. Different drugs and treatment modalities, such as bone marrow transplantation, have been entertained, and used without a significant impact on the disease or the overall survival.
Supportive care in multiple myeloma has advanced significantly over the past few years. Growth factor support with erythropoietin replacement and GM-CSF for stimulating the white blood cell (WBC) population are safe and effective methods of decreasing or preventing the occurrence or the severity of neutropenia. Also, high dose chemotherapy followed by autologous bone marrow or peripheral blood progenitor cell (PBMC) transplantation has recently increased the complete remission rate and remission duration. However, overall survival has only been slightly prolonged, and no evidence for a cure has been obtained. All patients ultimately relapse, even under maintenance therapy with interferon-α (IFN-α) alone or in combination with steroids. Adoptive immunotherapy rather than active vaccination may prove to be a more effective therapy for MM patients. There are relatively few known surface antigens on plasma cells that are suitable for antibody-directed treatment. Possible molecules include HM1.24, CD38, ICAM-1 (CD54), CD40, CD45, CD20, and syndecan 1. To date, there are no exclusive markers reported for MM. CD20, CD38, CD56 and CD130 are all markers that are expressed on normal B-cells, T-cells, or natural killer (NK) cells.
Ovarian cancer is the fifth leading cause of cancer deaths among U.S. women and has the highest mortality of any of the gynecologic cancers. It accounted for an estimated 26,600 new cases and 14,500 deaths in 1995. The overall 5-year survival rate is at least 75%, if the cancer is confined to the ovaries, and decreases to 17% in women diagnosed with distant metastases. Symptoms usually do not become apparent until the tumor compresses or invades adjacent structures, or ascites develops, or metastases become clinically evident. As a result, two thirds of women with ovarian cancer have advanced (Stage III or IV) disease at the time of diagnosis. Carcinoma of the ovary is most common in women over age 60. Other important risk factors include low parity and a family history of ovarian cancer. Less than 0.1% of women are affected by hereditary ovarian cancer syndrome, but these women may face a 40% lifetime risk of developing ovarian cancer.
Potential screening tests for ovarian cancer include the bimanual pelvic examination, the Papanicolaou (Pap) smear, tumor markers, and ultrasound imaging. The pelvic examination, which can detect a variety of gynecologic disorders, is of unknown sensitivity in detecting ovarian cancer. Although pelvic examinations can occasionally detect ovarian cancer, small, early-stage ovarian tumors are often not detected by palpation due to the deep anatomic location of the ovary. Thus, ovarian cancers detected by pelvic examination are generally advanced and associated with poor survival. The pelvic examination may also produce false positives when benign adnexal masses (e.g., functional cysts) are found. The Pap smear may occasionally reveal malignant ovarian cells, but it is not considered to be a valid screening test for ovarian carcinoma. Ultrasound imaging has also been evaluated as a screening test for ovarian cancer, since it is able to estimate ovarian size, detect masses as small as 1 cm, and distinguish solid lesions from cysts.
Serum tumor markers are often elevated in women with ovarian cancer. Examples of these markers include carcinoembryonic antigen, ovarian cystadenocarcinoma antigen, lipid-associated sialic acid, NB/70K, TAG 72.3, CA15-3, and CA-125, respectively. Evidence is limited on whether tumor markers become elevated early enough in the natural history of occult ovarian cancer to provide adequate sensitivity for screening. Tumor markers may have limited specificity. It has been reported that CA-125 is elevated in 1% of healthy women, 6-40% of women with benign masses (e.g., uterine fibroids, endometriosis, pancreatic pseudocyst, pulmonary hamartoma) and 29% of women with nongynecologic cancers (e.g., pancreas, stomach, colon, breast). Prospective studies involving asymptomatic women are needed, however, to provide definitive data on the performance characteristics of serum tests when used as screening tests.